HRP在大孔笼状介孔分子筛FDU-12上的固定及直接电化学

Immobilization and Direct Electrochemistry of Horseradish Peroxidase on Large Cage-Like Mesoporous Silica FDU-12

用吸附的方法将辣根过氧化物酶(HRP)固定到三维笼状介孔分子筛FDU-12中,傅立叶变换红外光谱(FTIR)和电化学交流阻抗谱结果表明,固定后的HRP没有变性,并表现出良好的直接电化学性质,其式量电位(E0′)为-0.325V,在40-300mV·s-1范围内,它不随扫描速率变化而变化.电化学反应速率常数(ks)为1.200s-1.固定后的HRP对H2O2有稳定的电催化活性,该固定酶的方法具有简单、易操作和电极稳定性良好等优点,可用于获得其他酶或氧化还原蛋白质的直接电子转移以及第三代生物传感器电极的制备.

We report on a direct electron transfer and bioelectrocatalysis of horseradish peroxidase （HRP） immobilized in mesoporous silica FDU-12 with three-dimensional （3D） large cages and entrances. UV-Vis spectroscopy, Fourier transform infrared （FTIR） spectroscopy, and impedance spectroscopy were used to prove the interaction between HRP and FDU-12. Results from cyclic voltammetry show that immobilized HRP can undergo a direct quasi-reversible electrochemical reaction. Its formal potential, E^0′, is -0.325 V in a phosphate buffer solution （PBS, pH 6.9） and this is almost independent of the scan rate from 40 to 300 mV·s^-1. The experimental results also demonstrate that the immobilized HRP retains its bioelectrocatalytic activity for the reduction of H2O2. Furthermore, the electrode can be stored at 4 ℃ for several weeks without any loss of enzyme activity. Thus, FDU-12 is a novel matrix for realizing a direct electron transfer of various proteins and enzymes and the preparation of electrodes for the third biosensors.